JPH0992503A - Metal oxide film resistor and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal oxide film resistor having a perfect resistance value of the specific value or higher and also having a small resistance temperature coefficient. SOLUTION: A metal oxide film resistor has a resistance film consisting of an Sn-Sb-M-O composite oxide (M is a metal selected from the group including Al, Cr, Fe and V). The desired range of ratio of Sb to Sn is 0.1 to 20%, and the ratio of M to Sn is 0.1 to 50%. The mixed gas or mist, containing stannic chloride, trichloro-antimon, halide salt of metal element M, and methanol, is brought into contact with heated base material, and an Sn-Sb-M-O composite film is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal oxide film resistor that is widely used when forming circuits of various electric devices and a method for manufacturing the same.

[0002]

2. Description of the Related Art As shown in FIG. 1, a metal oxide film resistor includes a rod-shaped insulating base material 1 such as mullite or alumina, and a tin oxide or antimony-added tin oxide (ATO) formed on the surface thereof. Metal oxide film 2, metal cap terminals 3 and 4 pressed into both ends of the base material, lead wires 5 and 6 welded to the terminals, and a protective film 7 formed on the surface of the resistor. Has been done. A material using a tin oxide single phase as the metal oxide coating material has a large specific resistance and a very large negative temperature coefficient (TCR) of the resistance value, so that the usage conditions are greatly limited and not practical. For this reason, in general, as a metal oxide film material, A having a small specific resistance and a TCR of a positive value or a value close to 0
TO has been put to practical use. This material has a high carrier concentration and has a positive TCR because the scattering effect of carriers due to lattice vibration is larger than the carrier concentration increase due to heat excitation energy when the temperature rises. Shows electrical conduction. As described above, in general, a material having a low specific resistance has a high carrier concentration and a TCR that is positive or close to 0, and a material having a large specific resistance has a low carrier concentration and a large negative TCR value. .

The metal oxide film resistor is manufactured by a chemical film forming method such as a spray method or a chemical vapor deposition method (CVD). In these methods, 60
By spraying the vapor of an aqueous solution or an organic solvent solution containing stannic chloride and antimony trichloride in a furnace heated to 0 to 800 ° C. onto a rod-shaped mullite-alumina substrate 1 An ATO film 2 is formed on top. Furthermore, the metal cap terminals 3 and 4 are press-fitted into both ends of the base material 1,
AT while rotating the substrate 1 so as to obtain a desired resistance value
A part of the O film 2 is trimmed by a diamond cutter or a laser, and the lead wires 5, 6 are attached to the cap terminals 3, 4.
After welding, the protective film 7 made of resin is formed to obtain a metal oxide film resistor. The complete resistance value of the metal oxide film resistor thus obtained varies depending on the film thickness of the ATO film and the number of trimming turns, and is generally 10Ω to 100 kΩ if the size of the substrate is constant.

[0004]

According to the above-described resistance adjusting method, in order to obtain a metal oxide film resistor having a completed resistance value of 100 kΩ or more, the thickness of the ATO film must be reduced or the ATO film must be thinned. A method of narrowing the trimming interval of the image is considered. However, the specific resistance of the ATO film is about 1 ×
Since it is 10 ⁻³ to 1 × 10 ⁻² Ω · cm, the film thickness must be considerably thinned in order to increase the resistance value.
At this time, there is a problem that the TCR becomes a large negative value because the strain of the film itself and the ratio of the depletion layer on the film surface to the entire film increase.

Further, since the initial resistance value of the ATO film is low, if the final resistance value is set to 100 kΩ or more, the number of turns of trimming by the laser increases, and it takes a very long time for trimming, and the trimming interval becomes long. There is also a problem that it becomes too narrow to physically trim. As described above, if the film thickness is too thin or the trimming interval is narrowed, the cross-sectional area of the electric conduction path is reduced and the contact area with the outside world is increased, which may cause electrical stress or changes in the outside world. It became weak and it was difficult to obtain a highly reliable metal oxide film resistor. An object of the present invention is to solve the above-mentioned problems, and an object thereof is to provide a metal oxide film resistor having a completed resistance value of 100 kΩ or more and a small TCR.

[0006]

The metal oxide film resistor of the present invention is a Sn-Sb-MO composite oxide (provided that
M represents a metal selected from the group consisting of Al, Cr, Fe and V. ). Where S
The ratio of the number of Sb atoms to n is 100 × Sb / Sn
It is preferably in the range of 0.1 at% to 20 at% expressed as (at%). Further, the ratio of the number of M atoms to Sn is expressed as 100 × M / Sn, and is 0.1 at% to 20.
It is preferably in the range of at%.

The method for producing a metal oxide film resistor according to the present invention comprises stannic chloride, antimony trichloride and a halide of a metal element M (where M is selected from the group consisting of Al, Cr, Fe and V). A mixed gas or mist containing metal) and methanol is brought into contact with the heated base material to form a Sn-Sb-MO composite oxide film. Here, the heating temperature of the base material is 500 to 9
Preferably it is 00 ° C. Further, the halide of the metal element M is preferably chloride.

The specific resistance of ATO which constitutes the metal oxide film resistor is approximately 1 depending on the manufacturing method and the amount of oxygen defects.
It is × 10 ⁻³ Ω · cm to 1 × 10 ⁻² Ω · cm. The Sn-Sb-MO composite oxide film of the present invention has a specific resistance of about 1 × 10 ⁻³ Ω by controlling the added amount of antimony, aluminum, chromium, iron and vanadium.
cm to ¹ × 10 ⁻¹ Ω · cm, it is possible to have a resistance value in a wider range in a region where the resistance is relatively higher than that of ATO.

In the production method of the present invention, when the mixed gas or mist comes into contact with the heated substrate, stannic chloride, antimony trichloride, and the halide salt of the metal element M are oxygenated in the atmosphere. Alternatively, since it reacts with an oxidizing agent such as water or alcohol to form a Sn—Sb—M—O-based complex oxide film, a film having good film quality is formed even in the concave portion of the substrate having a large surface roughness. . The specific resistance of the Sn-Sb-MO-based composite oxide film thus obtained is AT
Since the specific resistance of the O film is higher than that of the O film, the film thickness of the film can be made relatively large. As a result, the initial resistance value becomes high, the trimming becomes easy, and the TCR becomes small. As described above, according to the present invention, a highly reliable metal oxide film resistor can be stably manufactured.

Examples of the aluminum halide include aluminum trichloride, aluminum tribromide, aluminum triiodide and the like, with aluminum trichloride being preferred. Examples of chromium halides include chromium trichloride, chromium tribromide, and chromium triiodide, with chromium trichloride being preferred. Examples of iron halides include ferrous chloride, ferric chloride, ferrous bromide, ferric bromide, ferrous iodide, ferric iodide, etc. Is preferred. Examples of halides of vanadium include vanadium trichloride, vanadium tetrachloride, vanadium pentachloride, vanadyl dichloride, vanadyl trichloride, vanadium tetrabromide, vanadium tetraiodide, etc., but vanadyl dichloride and vanadyl trichloride are included. preferable. In addition, these added antimony, aluminum, chromium, iron, vanadium form a solid solution or a complex oxide with tin oxide, or become a metal oxide and are mixed with tin oxide. Conceivable.

[0011]

FIG. 1 shows a metal oxide film resistor according to one embodiment of the present invention. Insulating base material 1, metal oxide resistance film 2 formed on the base material 1, metal cap terminals 3 and 4 pressed into both ends of the base material 1, and lead wires 5 and 6 welded to the terminals. , And the protective film 7 formed on the surface of the resistor, except that the metal oxide resistance film 2 is different. Here, the base material 1 should just have an insulating property at least on the surface, and is preferably composed of a porcelain such as mullite, alumina, cordierite, forsterite, steatite. Further, the cap terminals 3 and 4 may be those which are ohmic-bonded to the resistance film 2, and the lead wires 5 and 6 are also cap terminals 3 and 4.
Any material can be used so long as it can be ohmic-bonded to No. 4. In addition,
The size in FIG. 1 is not necessarily accurate.

FIG. 2 shows the surface of a heated insulating substrate,
1 shows an apparatus for forming a metal oxide film by supplying a gas or mist of a resistance film forming composition comprising a metal oxide. Substrate 1 on which metal oxide is to be formed
The quartz reaction tube 11 containing the same is the quartz core tube 1 also made of quartz.
It is fixed inside 2 by packing 13. Electric furnace 1
The furnace core tube 12 inserted into the electric furnace 4 is driven by a driving device (not shown) and rotated in the electric furnace 14 at an appropriate rotational speed. The raw material supply device 16 containing the metal oxide film forming composition 15 is connected to a gas supply device 17 for supplying a carrier gas by a pipe 18 and is connected to the reaction tube 11 by a pipe 19. An exhaust device 21 is connected to the other end of the reaction tube 11 by a pipe 20.

In order to form a metal oxide film on the surface of a base material using this apparatus, the base material is first placed in the reaction tube 11 and set as shown, and the base material is heated by the electric furnace 14,
While maintaining the temperature at which the composition for forming a metal oxide film is thermally decomposed or higher, the reaction tube 11 is rotated. In this state, the carrier gas is sent from the gas supplier 17 to the raw material supplier 16 through the pipe 18, and the gas or mist of the metal oxide film forming composition is supplied to the reaction tube 11 through the pipe 19. The gas or mist supplied to the reaction tube 11 contacts the base material and decomposes to form a metal oxide film on the surface of the base material. Then, the undecomposed metal oxide film forming composition is sucked by the gas exhaust device 21, cooled, and collected.

The carrier gas supplied from the gas supplier 17 is air, oxygen, or an inert gas such as nitrogen or argon. The supply amount of the gas or mist can be controlled by the flow rate of the carrier gas. Further, the supply amount of the gas or mist can be controlled by heating the raw material supply device 16 or applying ultrasonic waves to the raw material supply device. The reaction tube 11 is rotated in order to uniformly form the metal oxide film on the substrate, and mechanical vibration may be applied instead of rotating the reaction tube 11. Further, there is no particular need to rotate the furnace core tube 12, and in this embodiment, the reaction tube 11 is not required.
Is fixed to the furnace core tube 12 in order to stabilize the rotation.

Example 1 A composition for forming a metal oxide film was synthesized as follows. In a 200 ml Erlenmeyer flask, 5 g of stannic chloride (SnCl ₄ .5H ₂ 0),
100 × Sb / Sn (at%) 0 to 30 at% antimony trichloride (SbCl ₃ ) and Al / Sn × 100
(At%) 0 to 60 at% aluminum trichloride (A
lCl ₃ ) was weighed, and 75 ml of methanol was added and dissolved to synthesize a composition for forming a metal oxide film.

Next, using the apparatus for producing a metal oxide film shown in FIG. 2, a columnar substrate 1 (outer diameter: 2 mm, having an alumina content of 92%) was used.
A metal oxide film was formed on the surface having a length of 10 mm. That is, the base material 1 was placed in the reaction tube 11, and the metal oxide film forming composition was placed in the raw material feeder 16. Air was used as the carrier gas, the gas flow rate was 1 liter / min, and the heating temperature of the substrate 1 was 800 ° C. The heating temperature of the base material 1 may be equal to or lower than the deformation temperature of the base material or the melting point of the metal oxide film 2, and the higher the heating temperature is, the better the film quality of the metal oxide film 2 is.
The temperature is preferably 00 to 900 ° C. After holding the substrate 1 in the reaction tube 11 at 800 ° C. for 30 minutes and sending 2.5 g of the composition for forming a metal oxide film into the reaction tube 11 for 10 minutes to form the metal oxide film 2, Furthermore, it hold | maintained at 800 degreeC for 10 minutes. The thickness of the coating film 2 thus formed is usually several tens to several thousands nm, but in the present embodiment, it was about 300 nm.

Substrate 1 on which the metal oxide film 2 is formed
After press-fitting tin-plated stainless steel cap terminals 3 and 4 on both ends of the and trimming for 8 turns with a diamond cutter, tin-plated copper lead wires 5 and 6 are attached to the cap terminals 3 and 4. Welded. Finally, a thermosetting resin paste is applied and dried on the surface of the metal oxide film 2 and heat-treated at 150 ° C. for 10 minutes to form an insulating protective film 7 to form a metal of the present invention. An oxide film resistor was obtained. The protective film 7 only needs to have insulating properties and moisture resistance, and as a material thereof, only resin or containing an inorganic filler may be used, and light such as visible light or ultraviolet light may be used for curing in addition to heat. Good.

The relationship between the composition of the obtained metal oxide film resistor, the finished resistance value and the TCR is shown in FIG. As shown in FIG. 3, as the metal oxide film resistor, it is preferable that the ratio of Sb to Sn is 0.1 at% to 20 at% and the ratio of Al to Sn is 0.1 at% to 50 at%. The ratio of Sb to Sn is 1 at% to 15 at
%, And the ratio of Al to Sn is most preferably in the range of 1 at% to 20 at%.

Example 2 In a 200 ml Erlenmeyer flask, 5 g of stannic chloride (SnCl ₄ .5H ₂ 0) and S were added.
b / Sn × 100 (at%) 0 to 30 at% antimony trichloride (SbCl ₃ ) and Cr / Sn × 100 (a
t%) 0 to 60 at% chromium trichloride (CrCl ₃ ).
Was weighed, 68 ml of methanol and 8 ml of hydrochloric acid were added and dissolved, and the obtained composition for forming a metal oxide film was used. Others were made similarly to Example 1, and produced the metal oxide film resistor. The thickness of the obtained metal oxide film 2 was about 300 nm in this example.

FIG. 4 shows the relationship between the composition of the obtained metal oxide film resistor, the finished resistance value and the TCR. As shown in FIG. 4, as the metal oxide film resistor, it is preferable that the ratio of Sb to Sn is 0.1 at% to 20 at% and the ratio of Cr to Sn is 0.1 at% to 50 at%. The ratio of Sb to Sn is 1 at% to 15 at
%, And the ratio of Cr to Sn is most preferably in the range of 1 at% to 30 at%.

Example 3 In a 200 ml Erlenmeyer flask, 5 g of stannic chloride (SnCl ₄ .5H ₂ 0) and S were added.
b / Sn × 100 (at%) 0 to 30 at% antimony trichloride (SbCl ₃ ) and Fe / Sn × 100 (a
(0% t%) of ferric chloride (FeCl ₃ ) of 0 to 60 at% was weighed, 68 ml of methanol and 8 ml of hydrochloric acid were added and dissolved, and the obtained composition for forming a metal oxide film was used. Others were made similarly to Example 1, and produced the metal oxide film resistor. The thickness of the obtained metal oxide film 2 was about 300 nm in this example.

The relationship between the composition of the obtained metal oxide film resistor, the finished resistance value and the TCR is shown in FIG. As shown in FIG. 5, as the metal oxide film resistor, it is preferable that the ratio of Sb to Sn is 0.1 at% to 20 at% and the ratio of Fe to Sn is 0.1 at% to 50 at%. The ratio of Sb to Sn is 1 at% to 15 at
%, The ratio of Fe to Sn is 0.2 at% to 40 at
Most preferably, it is in the range of%.

Example 4 In a 200 ml Erlenmeyer flask, 5 g of stannic chloride (SnCl ₄ .5H ₂ 0) and S were added.
b / Sn × 100 (at%) 0-30 at% antimony trichloride (SbCl ₃ ) and V / Sn × 100 (at
%) 0 to 60 at% vanadyl dichloride (VOCl ₂ )
Was weighed, 68 ml of methanol and 8 ml of hydrochloric acid were added and dissolved, and the obtained composition for forming a metal oxide film was used. Others were made similarly to Example 1, and produced the metal oxide film resistor. The thickness of the obtained metal oxide film 2 was about 300 nm in this example.

FIG. 6 shows the relationship between the composition of the obtained metal oxide film resistor, the finished resistance value and the TCR. As shown in FIG. 6, as the metal oxide film resistor, it is preferable that the ratio of Sb to Sn is 0.1 at% to 20 at% and the ratio of V to Sn is 0.1 at% to 50 at%. The ratio of Sb to Sn is 1 at% to 15 at
%, The ratio of V to Sn is 0.2 at% to 40 at%
Most preferably, it is within the range.

Comparative Example 1 In a 200 ml Erlenmeyer flask, 5 g of stannic chloride (SnCl ₄ .5H ₂ 0) and S were added.
b / Sn × 100 (at%) 0 to 30 at% antimony trichloride (SbCl ₃ ) was weighed, 68 ml of methanol and 8 ml of hydrochloric acid were added and dissolved, and the obtained composition for forming a metal oxide film was obtained. Was used. Others were made similarly to Example 1, and produced the metal oxide film resistor. The thickness of the obtained metal oxide film 2 was about 300 nm in this example. FIG. 7 shows the relationship between the composition of the obtained metal oxide film resistor, the completed resistance value, and the TCR.

[0026]

As described above, according to the present invention, a metal oxide film resistor having a wide range of resistance values and a small temperature coefficient of resistance value can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing a metal oxide film resistor according to an embodiment of the present invention.

FIG. 2 is a schematic vertical cross-sectional view showing a metal oxide film manufacturing apparatus in one embodiment of the present invention.

FIG. 3 shows a metal oxide film resistor (Sn-Sb-) of the present invention.
It is a graph which shows the composition of (Al-O type | system | group), the completion resistance value, and the relationship of TCR.

FIG. 4 is a metal oxide film resistor (Sn-Sb-) of the present invention.
It is a graph which shows the composition of (Cr-O type | system | group), a completion resistance value, and the relationship of TCR.

FIG. 5 shows a metal oxide film resistor (Sn-Sb-) of the present invention.
It is a graph which shows the composition of (Fe-O type | system | group), the completion resistance value, and the relationship of TCR.

FIG. 6 is a metal oxide film resistor (Sn-Sb-) of the present invention.
It is a graph which shows the composition of (VO system), completion resistance, and the relationship of TCR.

FIG. 7: Conventional metal oxide film resistor (Sn-Sb-O)
It is a graph which shows the relationship of the composition of (system), completion resistance value, and TCR.

[Explanation of symbols]

 1 Base Material 2 Metal Oxide Film 3, 4 Cap Terminal 5, 6 Lead Wire 7 Protective Film 11 Reaction Tube 12 Core Tube 13 Packing 14 Electric Furnace 15 Film Forming Composition 16 Raw Material Supplyer 17 Gas Supply Device 18, 19, 20 pipe 21 exhaust system

Claims (6)

[Claims] 1. A resistance film comprising a Sn—Sb—M—O-based composite oxide (where M represents a metal selected from the group consisting of Al, Cr, Fe and V). Metal oxide film resistors. 2. The ratio of Sb to Sn is 100 × S.
The metal oxide film resistor according to claim 1, wherein b / Sn (at%) is in a range of 0.1 at% to 20 at%. 3. The ratio of M to Sn is 100 × M /
The metal oxide film resistor according to claim 1 or 2, wherein Sn (at%) is in a range of 0.1 at% to 50 at%. 4. Stannous chloride, antimony trichloride, a halide of a metal element M (where M is Al, Cr, Fe)
And a metal selected from the group consisting of V. ), And a mixed gas or mist containing methanol are brought into contact with a heated base material to form a Sn-Sb-MO-based composite oxide film, and a method for producing a metal oxide film resistor. . 5. The method for producing a metal oxide film resistor according to claim 4, wherein the heating temperature of the base material is 500 to 900 ° C. 6. The method for producing a metal oxide film resistor according to claim 4, wherein the halide of the metal element M is chloride.